KALAMAZOO, MI -- Rev. Nathan Dannison is warning families of "vipers" who are exposing young boys to white supremacist ideas through the internet.

Dannison, a senior pastor at First Congregational Church in Kalamazoo, addressed hundreds of people who gathered in Bronson Park on Aug. 13 to denounce racial hatred displayed in Charlottesville, Va. during the weekend. Dannison continued his warning Monday in a Facebook post, listing a few red flags parents can watch for in their children.

"They are using chat rooms and video games; they are using the internet and YouTube channels to radicalize our young men," he said Sunday. "When they're 13-15 years old it starts out as a fun game. When they are 18; 19; 20-year-olds, they are practicing fascists. That is happening right now."

The pastor stressed the importance of parents being conscious of who their children are speaking to online, particularly white boys who may feel isolated. He said parents must explain the difference between patriotism and nationalism and be willing to contradict their children when they parrot hateful ideas.

"Introduce them to community; do not let them whither in the darkness," Dannison said. "Do not let their only contacts with adults be strangers on the internet who have political motivations."

James Alex Fields Jr., a 20-year-old Ohio man, was charged with second-degree murder in Charlottesville, after the authorities said he rammed a car into a line of other vehicles near protestors. A 32-year-old woman was killed, and 19 others were injured while protesting a rally staged by white nationalists.

In an interview with The Associated Press, his mother Samantha Bloom said she knew her son was going to a rally that "had something to do" with President Donald Trump, but she tried to "stay out of his political views."

Dannison said parents need to be more involved with what their kids are being exposed to.

Subsections of message boards have been known to spread talking points and highlight news stories coming from their preferred media sources. Online video games also allow the opportunity for children to speak to anonymous adults.

"I hope you heard your pastor, your leader, naming white supremacy as a sin against God almighty from the pulpit," Dannison said. "If you a part of a faith community, it is time for us to call to bear upon this country and declare that racism, white supremacy and fascism are sins against God and God's creation."